Pressure-gage for air-pumps.



' interese,

@siren siemens' rarnnr harmonic dienenden,- or oKniviiiH, exteriores'.

. it appertains to' make and use the same.

cluding improved means for automatically rihis invention is an improvement in` attachments for air pumps and 'has particular' reference to a pressure gage therefor.

The invention is especially adapted foruse inconnection with pumps roi' initiating automobile tires `and the like and has :tor

one .otits objects to provide a' simple and inexpensive,construction for readily ascertaining the pressure ina pneumatic tire.

`Another obyect is to provide al gageinreleasing'the air passing from the pump to the tire When a predetermined pressure in said tire is reached. i'

4'llhe inventive idea invblved is capable oi' receiving a varietybf mechanical expressions, one of Which,-or the purpose of illustrating the invention, is shown inthe accompanying drawing, Whereinz- Figure llis a fragmentary side ci an air pump of any desired vconstruction showing the pressure' gage applied thereto and constructed in accordance With the invention. A i F Fig. 2 is a vertical longitudinalsection through the gage.

i Fig. 3 is a perspective viev1 tubular member or the' gage. n

Fig. e is a transverse section on the line @il- 4 of Fig. 1. l

ln the drawing the numeral '5 `indicates an air pump of any desired construction of the inner provided Withthe usual flexible tube deze.

tending therefrom.

The .gage Which comprises the, essential feature of heinvention is adapted to' be. in-` terposed between the, body of the pump and the-tube` and preferably includesan innerA tubular member 7 having its inner or upper .end open .and provided at its lower end withV disposed threaded extensions 8f oppositely and A9 -the former -being vCODneCtedto-the y pump' 'While the latter has connected bo-.it

@ne .end oi the tube e.

' elevation Specification of Letters Patent.

Patented Aug. 13,191-f appunti@ meri 'any is, 1917. serial no. ironie. i

provided adjacent itsupper .end with 'the laterally eXtendi/ng pinl() and ata point diametrically o positc said 'pinv with a small openingLl-i-the iurpose oit which will appear later. c ,1.

The gage further comprises an outer tubular member l1,2 having its closed end 13 prloviided with a. small opening 14. The inner end of the outer member or housing 12 is .open and said member isi adapted' to be mounted overthe upper end of the member 7 and is .preferably provided with dia- 'uietrically disposed and longitudinally .ex-

. pressure Vvvitha rowof teeth 17 that are preferably tending slots`15 and 16 the former btwhich hasl oneiof its longitudinal edges provided numbered in' order to 'indicate the'dideren pounds'of pressure, any one of these notches beingA adapt'd to be engaged by the pin 1'0 of the memp'er 7. n f The members? preferably has mounted therein thepiston head 18 carried lby a rod 19` which eXtei-iii's longitudinally of lsaid member and thrb'ugh the opening 14C' in the topor closedend 13 of the'meniber 12 and said rod is also graduated `tofindicate. the of the iiuid passing from the pump 6. interposed betvieen I the member 12 'and the piston liead'land surrounding the rd 19 is av coil spring 2 0 which forces the piston 5 through the tube the closed end 13 of 18 inwardly against the pressure of air. The

the pressure in pin '10 from the notch and then forced down- `vvardly or inwardly toward the tube 6 until the pin 10 is adjacent the notch 17 opposite which the vdesired amount of pressure is in- "dicated The member 12 is then rotated to engage the pin 10 with the notch and when so 4engaged the pin will he held in contact with thelower edge of the notch' by the ricvtion induced 'by vthe.pressure of the spring The member' d' is adjustment@ themember 12 will `vcompress the spring 20 andl place the same under a" heavy tension whichinust be overcome by the pressure 1n thetirein order .to

raise the piston 18 until the same .passes the openngfll, 1f only a small amount of presith one 'of the notches 1T adjacent tiepl'aeet1'n; spring` 2()i under less tension and therefore there will be less pressure required to force the piston 18 past the opening 1l.

Vhat'is, claimed is 1. A pressure gage eomprismgan' .inner tubular member having one end opened and provided adjacent said end with a pin and ,an opening, the other end of said member having lateral extensions adapted to be connectedtoan air ump and tube thereo t` ..and a second adjusta le tubular member mount- -d over th'e irst named member and having oneend c1osed-and provided with an openling', said second member being also provided with longitudinal slots, one edge of one slot havingr'aek teeth adapted to be engaged by said pin-.to retain said'second member in ad- -justed positions a piston operable in the rfst named carrying said piston and extending through e. lower end ot' the member 12 which will @tension of which said piston operates,l and means for retaining the inner and outer members in relatively adjusted positions to vary the tension of said resilient means.

3. A pressure gage comprising relatively adjustable and teleseoping tubular members, a piston operable under pressure inthe inner member and relative to said members,l pressure rea-ding mea-ns movable with said piston, resilient means interposed betweensaid piston and the outer member and against the tension of which said piston 0perates, teeth formed upon said outer member, anda pin carried by the inner member and engageable with said teeth to retain said members in adjusted positions whereby to vary the' tension ot' said resilient means.'

4In testimony whereof I atiix my signature Ain the presence of two witnesses. ,V

RAYMOND C. 'BMCiiR'FH. l

lVitnesse's V. K. Criowmmn C.H. MCGRATH. 

